Re:Silicon die analysis: inside an op amp with interesting “...
by coupdejarnac on Sunday June 24, 2018 @01:57AM
(#17385166)
Is there a general purpose op amp that is the modern equivalent of the 741? Something with a much more recent design with widespread use.
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Re:Silicon die analysis: inside an op amp with interesting “...
by zokier on Sunday June 24, 2018 @08:02AM
(#17386211)
I doubt there is anything recent as iconic. Overall I think we have moved way beyond having individual generic iconic models at all. Digikey has like thousands (hundreds if you are old-fashioned and want through-hole) of different opamps which probably are mostly interchangeable 741 for most purposes, just pick any one of them.
Re:Silicon die analysis: inside an op amp with interesting “...
by hatsunearu on Sunday June 24, 2018 @02:07AM
(#17385202)
Also, there ARE objectively shit op amps that are old and crusty that pretty much nobody uses. I think it was the LM358 that basically had a broken output stage (class-B) that causes horrible output crossover distortion when you transition from sourcing to sinking current or vice versa.
http://www.ti.com/lit/ds/symlink/lm158-n.pdf
Page 13, Figure 16.
Q12 is a common emitter amplifier with an active load, that feeds directly into a class B output stage (pullup is a darlington with Q5 and Q6, and pulldown is Q13, with Q7 being a current limiter). I've never used this personally (for good reason) but I remember my mentors telling me this causes horrible CO distortion.
Re:Silicon die analysis: inside an op amp with interesting “...
by hatsunearu on Sunday June 24, 2018 @02:01AM
(#17385179)
What's wrong with the 741?
The 071 is also "jellybean" enough; both are still currently used in modern designs because how dirt cheap they are.
But they are "high voltage", non rail-to-rail anything, so people tend to use more modern options for new designs.
Re:Silicon die analysis: inside an op amp with interesting “...
by setquk on Sunday June 24, 2018 @07:19AM
(#17386063)
741 problems: terrible bias current, offset, input range, output range, power consumption, voltage requirements, GBW, noise.
They’re just horrid. Fine for noddy stuff like power supplies and PID loops etc though.
Re:Silicon die analysis: inside an op amp with interesting “...
by coupdejarnac on Sunday June 24, 2018 @07:27PM
(#17388937)
I don't have any particular problem with it. I majored in EE about 15 years ago, and haven't really looked at op amps since studying the 741. Just curious what's popular these days.